Space

A Polish mathematician and astronomer Nicolaus Copernicus discovered the planet Earth. Before Copernicus' ideas, people thought that the other planets, stars and the Sun rotated around the Earth. Ancient astronomers found that the planets wouldn't follow a straight path in the sky but would instead continually move forward, stop then move backwards, which caused the Greek astronomer Ptolemy to hypothesise that the planets are spherical in shape and rotate in small circles while moving around the Earth. Copernicus' model went against this belief and took years to be recognised by the scientific community. As the only known planet that is habitable for human beings, the Earth’s importance is self-evident. Every living organism known to science obtains all of its resources from Earth, and has very few other options available. Without the Earth, humans would be doomed to extinction, unless they were able to adapt to another planet's conditions before the Earth disappeared.